Discussion
Any views on which is the better engine?
Is there much difference in mpg/power - is one better than the other for a lpg conversion?
I`m looking for a mid 1990`s rr.
Are there any known issues with either engine? - I`m guessing most problems would have surfaced by now on a 15+ year old engine.
Is there much difference in mpg/power - is one better than the other for a lpg conversion?
I`m looking for a mid 1990`s rr.
Are there any known issues with either engine? - I`m guessing most problems would have surfaced by now on a 15+ year old engine.
Which Range rover are you thinking off, the 3.9 is in a classic Rangie and the 4.6 & 4.0 is in the p38. The classic Range rover I believe finnished in 93. If its the p38 the 4.6 seemed to suffer more than then the 4.0 from slipped liners etc,also if it is a p38 you are after there are a whole host of other things to consider.
Mick
Mick
It`s a continuation from this topic last night.......
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Thought it better to move over to this part of the forum as here is more relevant.
The age of RR i`m researching (1990-1995) covers the overlap between Classic and P38.
TBH I prefer the look of the P38 over the classic but realise it wasn`t available in 3.9.
I`ve read all sorts of horror stories of slipped liners in 4.0,4.2 and 4.6, but wondered what other differences there were in the engines.
I`m thinking a late model classic would have most design problems ironed out whereas very early P38`s may not.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Thought it better to move over to this part of the forum as here is more relevant.
The age of RR i`m researching (1990-1995) covers the overlap between Classic and P38.
TBH I prefer the look of the P38 over the classic but realise it wasn`t available in 3.9.
I`ve read all sorts of horror stories of slipped liners in 4.0,4.2 and 4.6, but wondered what other differences there were in the engines.
I`m thinking a late model classic would have most design problems ironed out whereas very early P38`s may not.
I've had a 3.9 Classic, 4.6 P38, 4.2 supercharged tomcat and now I have a 4.4 BMW powered L322 RR.
I may have been luck but I have never had a problem with the rover V8. The most problematic range rover I have had is the one L322 that I have now, Luckily I can do my own repairs so that keeps costs down.
I have had LPG on the firsts Classic and now on the L322 didn't bother with the P38. I love the sound of the Rover V8 its power is nothing compared to modern engines but certainly keeps the Range rover moving without drama.
If its a late classic (which if you can get a nice one is a great car and probably starting to appreciate)the only choice of engine is the 3.9 in the standard car or a 4.2 in LSE which is a slightly stretched RR.
I have also had a 3.5 V8 MGB which was a lot of fun and I am now looking for a V8 Defender.
Mick
I may have been luck but I have never had a problem with the rover V8. The most problematic range rover I have had is the one L322 that I have now, Luckily I can do my own repairs so that keeps costs down.
I have had LPG on the firsts Classic and now on the L322 didn't bother with the P38. I love the sound of the Rover V8 its power is nothing compared to modern engines but certainly keeps the Range rover moving without drama.
If its a late classic (which if you can get a nice one is a great car and probably starting to appreciate)the only choice of engine is the 3.9 in the standard car or a 4.2 in LSE which is a slightly stretched RR.
I have also had a 3.5 V8 MGB which was a lot of fun and I am now looking for a V8 Defender.
Mick
I see there is quite a difference in average price between the last of the classics and the first of the P38s.
Is this because the classics are now appreciating in price or is there a difference in reliability?
When did air suspension become available - is it worth it or are there reliability issues?
Is this because the classics are now appreciating in price or is there a difference in reliability?
When did air suspension become available - is it worth it or are there reliability issues?
RV8 Engines (and its been a few years since i was tinkering with them properly) fall into 3/4ish categories.
The 3.5s are virtually all interchangeable block/heads/pistons/front covers etc (barring a few odditiy old ones, which had rope seals).
The 3.9s and 4.2s are a sister block- bigger bores (94mm) and bigger crank. They can both suffer from porosity and slipped liners- the ONLY way to probably cure them is some sort of top hat liner sleeve which seals the head gasket to the top of the sleeve rather than to the block.
The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
The 3.5s are virtually all interchangeable block/heads/pistons/front covers etc (barring a few odditiy old ones, which had rope seals).
The 3.9s and 4.2s are a sister block- bigger bores (94mm) and bigger crank. They can both suffer from porosity and slipped liners- the ONLY way to probably cure them is some sort of top hat liner sleeve which seals the head gasket to the top of the sleeve rather than to the block.
The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
PugwasHDJ80 said:
The 3.9s and 4.2s are a sister block- bigger bores (94mm) and bigger crank. They can both suffer from porosity and slipped liners- the ONLY way to probably cure them is some sort of top hat liner sleeve which seals the head gasket to the top of the sleeve rather than to the block.
The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
If I recall correctly it was the 4.6 engine which suffered the most from slipped liners possibly resulting from lean fuelling causing it to run hot and the block not having fantastic coolant routing. ACR (amongst others) have cured this with "top hat" liners; Roland Marlow of ACR is probably one of the best sources of facts concerning Rover V8s and what is possible. The 4.6 will produce a more torque than a 3.9 but at reduced efficiency when not working hard - what do you plan on using the vehicle for?The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
100SRV said:
If I recall correctly it was the 4.6 engine which suffered the most from slipped liners possibly resulting from lean fuelling causing it to run hot and the block not having fantastic coolant routing. ACR (amongst others) have cured this with "top hat" liners; Roland Marlow of ACR is probably one of the best sources of facts concerning Rover V8s and what is possible. The 4.6 will produce a more torque than a 3.9 but at reduced efficiency when not working hard - what do you plan on using the vehicle for?
To be used day to day for everything from the weekly shop to towing a couple of tonnes - sometimes on long 1000mile+ European trips.I`m guessing the later blocks won`t be as well suited to LPG due to the higher temps affecting liners?
Without been rude and trying to put you off, if you got for a P38 make sure you are willing to have a fund for things going wrong.
I had a 2002 P38 4litre and it was the worst car I ever owned.
Was a low mileage 2 owner vehicle and dealer maintained.
But it still went very wrong and they are not best suited to LPG, have you thought about Jeep Grand Cherokee's?
Not as much road presence but I have had one for 2yrs and its been brilliant and on LPG, its quick been a V8 high output as well.
I had a 2002 P38 4litre and it was the worst car I ever owned.
Was a low mileage 2 owner vehicle and dealer maintained.
But it still went very wrong and they are not best suited to LPG, have you thought about Jeep Grand Cherokee's?
Not as much road presence but I have had one for 2yrs and its been brilliant and on LPG, its quick been a V8 high output as well.
you can use a serp front cover on any of the previous RV8s - the last of the 3.9 & 4.2s had a serp front. the only real difference between the blocks are the 4.0/4.6s have larger crank journals and cant be used on the earlier engines.
PugwasHDJ80 said:
RV8 Engines (and its been a few years since i was tinkering with them properly) fall into 3/4ish categories.
The 3.5s are virtually all interchangeable block/heads/pistons/front covers etc (barring a few odditiy old ones, which had rope seals).
The 3.9s and 4.2s are a sister block- bigger bores (94mm) and bigger crank. They can both suffer from porosity and slipped liners- the ONLY way to probably cure them is some sort of top hat liner sleeve which seals the head gasket to the top of the sleeve rather than to the block.
The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
The 3.5s are virtually all interchangeable block/heads/pistons/front covers etc (barring a few odditiy old ones, which had rope seals).
The 3.9s and 4.2s are a sister block- bigger bores (94mm) and bigger crank. They can both suffer from porosity and slipped liners- the ONLY way to probably cure them is some sort of top hat liner sleeve which seals the head gasket to the top of the sleeve rather than to the block.
The 4.0s and 4.6s are a different beast again- very few parts are easily interchangeable between the these and the earlier blocks- the cranks are different sizes, and different lengths, and to confuse things further they even (mostly) had different oil pumps- so you can't use a serpentine front end on a 3.9 block.
so the base of it for me is that if you want anything other than a 3.5 then you are gonig to suffer the risk of porosity or slipper liners. Hence you might as well get the biggest engine you can- the latter engines are also potentially stronger because they can be cross-bolted on the main caps which increasese stiffness along the crank (although in every day use imo it will never make much difference). the other thing about the 4.0/4.6 is that they tend to seem to be more reliable, with better electronics-which always helps.
oh and they'll be newere too!
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